19-1201; Rev 0; 3/97
E
MODUL
6811D
BLE
AVAILA
MAX1110 Evaluation System/
Evaluation Kit
____________________________Features
o
Proven PC Board Layout
o
Complete Evaluation System Samples to 5ksps
o
Convenient Test Points Provided on Board
o
Data-Logging Software
o
Fully Assembled and Tested
_______________General Description
The MAX1110 evaluation system (EV system) is a com-
plete, 8-channel data-acquisition system consisting of a
MAX1110 evaluation kit (EV kit) and a Maxim 3V 68L11D
microcontroller (µC) module. It is designed to evaluate
the MAX1110, a low-power, +3V, 8-channel, 8-bit ana-
log-to-digital converter (ADC) with an internal 2.048V ref-
erence that directly interfaces to 3V microprocessors.
Windows 3.1
®
/Windows 95
®
software provides a handy
user interface to exercise the MAX1110’s features.
The EV system is intended for comprehensive evalua-
tion of the MAX1110 using a personal computer. Order
the stand-alone EV kit if the 68L11D µC module has
already been purchased with a previous Maxim EV sys-
tem, or for custom use in other µC-based systems.
The MAX1110 EV kit and EV system can also be used to
evaluate the MAX1112, which operates on +5V and has
a 4.096V internal reference. Simply order a free sample
of the MAX1112CPP along with the MAX1110 EV kit.
Evaluates: MAX1110/MAX1112
______________Ordering Information
PART
MAX1110EVKIT-DIP
MAX1110EVL11-DIP
TEMP. RANGE
0°C to +70°C
0°C to +70°C
BOARD TYPE
Surface Mount
Surface Mount
MAX1110 EV System
____________________Component List
PART
MAX1110EVKIT-DIP
68L11DMODULE
QTY
1
1
DESCRIPTION
MAX1110 evaluation kit
68L11D µC module
_____MAX1110 Stand-Alone EV Kit
The MAX1110 EV kit provides a proven PC board lay-
out to facilitate evaluation of the MAX1110. It must be
interfaced to appropriate timing signals for proper
operation. Refer to the MAX1110 data sheet for timing
requirements. Apply your supply voltage between the
VDD pad and the GND pad. Refer to Table 1 for jumper
configurations.
MAX1110 EV Kit
____________________Component List
DESIGNATION QTY
C1–C8
C9, C11
C10
J1
J2
JU1, JU2, JU3
JU4
JU5
R1–R8
R9
U1
U1
None
None
8
2
1
1
1
3
1
0
8
1
1
1
1
1
DESCRIPTION
0.01µF ceramic capacitors
4.7µF, 10V tantalum capacitors
0.1µF ceramic capacitor
2x20 right-angle socket
8-pin header
2-pin jumper blocks
3-pin jumper block
Open
10kΩ, 5% resistors
10Ω, 5% resistor
Maxim MAX1110CPP
20-pin socket
PC board
Software disk,
“MAX1110 EVALUATION KIT”
______________MAX1110 EV System
The MAX1110 EV system operates from a user-sup-
plied 9V to 15V DC power supply. The Maxim 68L11D
3V µC board uses a MAX667 linear regulator to gener-
ate the 3V logic supply.
Quick Start
1) Install the MAX1110 EV kit software on your comput-
er by running the INSTALL.EXE program on the flop-
py disk. The program files are copied and icons are
created for them in the Windows 3.1 Program
Manager (or the Windows 95 Start Menu).
2) Check the jumper settings on the MAX1110 EV kit
board. Refer to Table 1,
Jumper Functions
, and
Table 2,
Default Jumper Settings.
3) Carefully connect the boards by aligning the 40-pin
header of the MAX1110 EV kit with the 40-pin con-
nector of the µC module. Gently press them togeth-
er. The two boards should be flush against one
another.
1
Windows is a registered trademark of Microsoft Corp.
________________________________________________________________
Maxim Integrated Products
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX1110 Evaluation System/
Evaluation Kit
Evaluates: MAX1110/MAX1112
4) Connect a 9V to 15V DC power source to the µC
module at the terminal block located next to the
on/off switch, in the upper-right corner of the µC
module. Observe the polarity marked on the board.
5) Connect a cable from the computer’s serial port to
the µC module. If using a 9-pin serial port, connect
a straight-through, 9-pin female-to-male cable. If the
only available serial port uses a 25-pin connector, a
standard 25-pin to 9-pin adapter is required. The EV
kit software checks the modem status lines (CTS,
DSR, DCD) to confirm that the correct port has been
selected.
6) Start the MAX1110 program by opening its icon in
the Program Manager (or Start Menu).
7) The program prompts you to connect the µC mod-
ule and turn its power on. Slide SW1 to the ON posi-
tion. Select the correct serial port, and click OK. The
program automatically downloads KIT1110.L11 to
the module.
8) Apply input signals to the CH0–CH7 inputs at the
right edge of the MAX1110 EV kit board. Observe
the readout on the screen.
power-up delay requirement depends on the value of
the reference capacitor (C9) and the off-time (delay
between samples).
The MAX1110 EV kit software performs power-up by
starting a conversion and discarding the reading. When
the power-up delay is complete, the reference voltage
is correct, and an accurate measurement can be per-
formed.
Measuring Supply Current
On the EV kit board, the MAX1110 draws all its power
through jumper JU5, which is wired closed when the
board is shipped from the factory. To measure the
MAX1110’s supply current, modify the board (with the
power off) by cutting jumper JU5 and connecting a cur-
rent meter across JU5.
Low-Speed Data Logging
The RS-232 serial link limits the data-logging sample
rate to no more than 10 samples per second. The Log
menu can be used to write data to a user-specified file
in comma-spaced-value text format. From the Log
menu, select Select Channels, and select the channels
you want to log. Next, pick the New Log File command
from the Log menu. Once a log file has been opened, it
can be paused or resumed with the Pause command.
One complete line of data is written after all enabled
channels have been sampled. The first line of the log
file contains the column headings. Each subsequent
line of the log file contains all enabled channels, sepa-
rated by commas, tabs, or spaces. The program con-
tinues to write data to the log file until the Done com-
mand is selected from the Log menu.
Evaluating the MAX1112
To evaluate the MAX1112, turn off power to the kit,
replace U1 with a MAX1112CPP, and set V
DD
to 5V by
adjusting trim pot R2 on the 68L11D module. No other
hardware changes are necessary. Start the MAX1110
software, and change the assumed reference voltage
from 2.048V to 4.096V. Refer to the section
Changing
the Reference Voltage.
__Detailed Description of Software
Shutdown Power Cycling
To reduce average supply-current demand, the
MAX1110 can be shut down between conversions.
From the Power menu, select Full Power-Down mode.
The amount of power savings depends primarily on
how long the part is off between conversions. The
accuracy of the conversions depends on the power-up
delay, the reference capacitor, and the time in power-
down. Adjust the off-time with the Delay Between
Samples command. Adjust the on-time with the Power-
Up Delay command.
Using an adequate power-up delay ensures conversion
accuracy during power-cycling modes. The reference
must be allowed enough time to stabilize before the
measurement is performed. The Power-Up Delay com-
mand controls the power-up delay. Increase the delay
until no further change in accuracy is observed. The
High-Speed Data Sampling
For sampling rates up to 5ksps, the high-speed sam-
pling commands can be used. Data can be collected
from any single channel at high speed, using the com-
mands on the Sample menu. First, select the number of
samples. Then, set the sampling rate by inserting a
delay between samples, or choosing one of the preset
sample rates. To begin collecting data, use the Collect
command. After the samples have been collected, the
data is automatically uploaded to the host and is
graphed. The data can optionally be saved to a file.
Changing the Reference Voltage
The MAX1110 EV kit software assumes a 2.048V refer-
ence voltage, unless otherwise specified. To change
the reference voltage assumption, use Set Reference
Voltage under the Device menu.
2
_______________________________________________________________________________________
MAX1110 Evaluation System/
Evaluation Kit
Detailed Description
________________________of Hardware
U1, the MAX1110, is an 8-channel, 8-bit, low-power
analog-to-digital converter (ADC) with serial interface
and a shutdown mode. R1–R8 and C1–C8 act as anti-
aliasing input filters. V
DD
and GND are the analog sup-
ply rails. Refer to the MAX1110 data sheet for additional
information.
C9 and C11 are 4.7µF bypass capacitors for the refer-
ence and the power supply. For reduced board size
and/or lower cost, C9 and C11 may be reduced to 1µF.
R9 and C10 filter the digital noise out of the analog
power supply.
Evaluates: MAX1110/MAX1112
Input Filtering
The EV kit has an RC filter on each input with a time con-
stant of approximately 100µs (R = 10kΩ, C = 0.01µF).
Acquisition time with a 500kHz clock is 4µs. The RC fil-
ter’s settling time may increase the acquisition time
required for full accuracy when switching input channels.
Table 1. Jumper Functions
JUMPER
STATE
open
JU1
closed
open
closed
JU3
open
closed
open
JU4
1–2
2–3
JU5
closed
open
FUNCTION
Use an external user-supplied refer-
ence.
Use the internal reference (REFIN is
connected to REFOUT).
Analog common voltage must be set
by user.
Analog common (COM) = GND.
SHDN
is allowed to float or be driven
by JU4.
SHDN
is driven by the µC module.
MAX1110 is active with internal
reference enabled.
SHDN
= V
DD
; MAX1110 is active with
internal reference disabled.
SHDN
= GND; MAX1110 is inactive.
Current-sense jumper. The MAX1110
draws its power through this trace.
Do not operate kit with JU5 open.
Table 2. Default Jumper Settings
JUMPER
JU1
JU2
JU3
JU4
JU5
STATE
closed
closed
open
open
closed
FUNCTION
Use the internal reference (REFIN is
connected to REFOUT).
COM = GND.
SHDN
is allowed to float or be driven
by JU4.
MAX1110 is active with internal refer-
ence enabled.
The MAX1110 draws its power through
this trace.
JU2
_______________________________________________________________________________________
3
MAX1110 Evaluation System/
Evaluation Kit
Evaluates: MAX1110/MAX1112
Listing 1. MAX1110 Pseudo-Code Example
4
_______________________________________________________________________________________
MAX1110 Evaluation System/
Evaluation Kit
Evaluates: MAX1110/MAX1112
Listing 2. Bit-Banging Substitute for SPI Port
_______________________________________________________________________________________
5
Embedded System
京公网安备 11010802033920号
EEWORLD
